The present disclosed subject matter relates generally to a transperineal prostate needle biopsy system and method, and more particularly to a biopsy needle used in conjunction with imaging and planning software to identify and treat lesions of the prostate.
Prostate cancer is the most frequently diagnosed solid tumor in men and second leading cause of cancer death in the United States. Early detection and treatment of such tumors has progressively decreased the age-adjusted death rates. A diagnosis of a prostate tumor may be confirmed by a biopsy and assessment of the suspect tissue.
The standard biopsy needle used to confirm a diagnosis of prostate cancer consists of a fixed length core bed. Such a needle, and similar devices, are designed to be used in conjunction with a transrectal ultrasound probe allowing real time imaging of the prostate gland as biopsies are being performed. When transrectal ultrasound was originally introduced large prostate cancer lesions were easily identifiable by ultrasound imaging allowing an operator to see a representative image of the prostate and lesions at the time of biopsy. The wide application of prostate specific antigen (PSA) screening has allowed for the detection of smaller and smaller prostate cancer lesions thereby making visualization of such discrete lesions unlikely when using ultrasound alone. Today, the typical patient presents with an elevated PSA and no discernible lesion on physical exam or by ultrasound exam.
During a typical needle biopsy procedure a urologist uses a traditional transrectal ultrasound-guided approach taking multiple individual biopsies trying to sample the lateral regions of the gland in what amounts to a semi “blind” approach. A patient undergoing this type of procedure has a 20-30% chance of having a cancer diagnosed. A majority of these cancers are low grade. With 240,000 new cases of prostate cancer expected in the United States in 2013, over 75% will be considered low risk cancers meaning these cancers have a low likelihood of being the principle cause of a patient's death. However, biopsy specimens retrieved using the blind approach often leads to inconclusive results. For example, in 50-75% of the situations when a transrectal biopsy is followed by a radical prostatectomy (removal of the entire prostate gland) the pathology predicted by the biopsy is not representative of the final specimen.
Data from radical prostatectomy specimens demonstrates a high likelihood of bilateral and multifocal disease. In a study of 2,388 specimens, the incidence of multifocal lesions ranged from 33%-87% (average 67.6% for 12 studies). Of the more than 180,000 new prostate cancer diagnoses that are found to be low risk on biopsy today, only a third would meet the criteria for observation (no active treatment). The other two-thirds would be candidates for complete or focal (partial) therapy. Identifying these candidates based on transrectal biopsy is extraordinarily difficult, if not impossible. In a study 538 low-risk prostatectomy specimens were examined with the goal of looking for pretreatment characteristics to accurately identify patients for focal therapy. A total of 6 to 16 cores were taken by transrectal biopsy and the median number of positive cores was 1 (range, 1-12). When the prostatectomy specimens were examined, upgrading to Gleason Score (GS) 8-10 occurred in 6.3%. Extracapsular extension was found in 19% and seminal vesicle involvement in 2.4%. Although unilateral disease was found by biopsy in 71% of the patients, it was present in only 22.5% of the prostatectomy specimens.
Based on current data, if accurate prostate biopsies could be performed, a treatment algorithm for an estimated 240,000 new prostate cancer cases (United States) as diagnosed by current biopsy procedures would yield approximately 210,00 candidates with a low grade lesion (GS 6-7) who would be candidates for transperineal mapping (TPM) biopsies and approximately 30,000 candidates with higher grade lesions (GS 8-10) who would be candidates for a radical prostatectomy (RP) or radiotherapy (RT) (FIG. 1). Of the approximately 210,000 candidates undergoing TPM for further examination, approximately 20,000 would yield high grade lesions (GS 8-10) who would be candidates for RP or RT (FIG. 2). Of the remaining approximately 190,000 having undergone TPM, approximately 33 percent would warrant active surveillance (AS), approximately 33 percent would warrant RP or RT, and approximately 33 percent would warrant focal therapy. With improved tools and technology a larger number of candidates could avoid RP or RT.